1/*-
2 * Copyright (c) 2002 Daniel Eischen <deischen@freebsd.org>.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28/*
29 * Machine-dependent thread prototypes/definitions for the thread kernel.
30 */
31#ifndef _PTHREAD_MD_H_
32#define	_PTHREAD_MD_H_
33
34#include <stddef.h>
35#include <sys/types.h>
36#include <sys/kse.h>
37#include <machine/sysarch.h>
38#include <ucontext.h>
39
40extern int _thr_setcontext(mcontext_t *, intptr_t, intptr_t *);
41extern int _thr_getcontext(mcontext_t *);
42
43#define	KSE_STACKSIZE		16384
44#define	DTV_OFFSET		offsetof(struct tcb, tcb_dtv)
45
46#define	THR_GETCONTEXT(ucp)	_thr_getcontext(&(ucp)->uc_mcontext)
47#define	THR_SETCONTEXT(ucp)	_thr_setcontext(&(ucp)->uc_mcontext, 0, NULL)
48
49#define	PER_KSE
50#undef	PER_THREAD
51
52struct kse;
53struct pthread;
54
55/*
56 * %gs points to a struct kcb.
57 */
58struct kcb {
59	struct tcb		*kcb_curtcb;
60	struct kcb		*kcb_self;	/* self reference */
61	struct kse		*kcb_kse;
62	struct kse_mailbox	kcb_kmbx;
63};
64
65struct tcb {
66	struct tcb		*tcb_self;	/* required by rtld */
67	void			*tcb_dtv;	/* required by rtld */
68	struct pthread		*tcb_thread;
69	void			*tcb_spare;	/* align tcb_tmbx to 16 bytes */
70	struct kse_thr_mailbox	tcb_tmbx;
71};
72
73/*
74 * Evaluates to the byte offset of the per-kse variable name.
75 */
76#define	__kcb_offset(name)	__offsetof(struct kcb, name)
77
78/*
79 * Evaluates to the type of the per-kse variable name.
80 */
81#define	__kcb_type(name)	__typeof(((struct kcb *)0)->name)
82
83/*
84 * Evaluates to the value of the per-kse variable name.
85 */
86#define	KCB_GET32(name) ({					\
87	__kcb_type(name) __result;				\
88								\
89	u_int __i;						\
90	__asm __volatile("movl %%gs:%1, %0"			\
91	    : "=r" (__i)					\
92	    : "m" (*(u_int *)(__kcb_offset(name))));		\
93	__result = (__kcb_type(name))__i;			\
94								\
95	__result;						\
96})
97
98/*
99 * Sets the value of the per-kse variable name to value val.
100 */
101#define	KCB_SET32(name, val) ({					\
102	__kcb_type(name) __val = (val);				\
103								\
104	u_int __i;						\
105	__i = (u_int)__val;					\
106	__asm __volatile("movl %1,%%gs:%0"			\
107	    : "=m" (*(u_int *)(__kcb_offset(name)))		\
108	    : "r" (__i));					\
109})
110
111static __inline u_long
112__kcb_readandclear32(volatile u_long *addr)
113{
114	u_long result;
115
116	__asm __volatile (
117	    "	xorl	%0, %0;"
118	    "	xchgl	%%gs:%1, %0;"
119	    "# __kcb_readandclear32"
120	    : "=&r" (result)
121	    : "m" (*addr));
122	return (result);
123}
124
125#define	KCB_READANDCLEAR32(name) ({				\
126	__kcb_type(name) __result;				\
127								\
128	__result = (__kcb_type(name))				\
129	    __kcb_readandclear32((u_long *)__kcb_offset(name)); \
130	__result;						\
131})
132
133
134#define	_kcb_curkcb()		KCB_GET32(kcb_self)
135#define	_kcb_curtcb()		KCB_GET32(kcb_curtcb)
136#define	_kcb_curkse()		((struct kse *)KCB_GET32(kcb_kmbx.km_udata))
137#define	_kcb_get_tmbx()		KCB_GET32(kcb_kmbx.km_curthread)
138#define	_kcb_set_tmbx(value)	KCB_SET32(kcb_kmbx.km_curthread, (void *)value)
139#define	_kcb_readandclear_tmbx() KCB_READANDCLEAR32(kcb_kmbx.km_curthread)
140
141
142/*
143 * The constructors.
144 */
145struct tcb	*_tcb_ctor(struct pthread *, int);
146void		_tcb_dtor(struct tcb *tcb);
147struct kcb	*_kcb_ctor(struct kse *);
148void		_kcb_dtor(struct kcb *);
149
150/* Called from the KSE to set its private data. */
151static __inline void
152_kcb_set(struct kcb *kcb)
153{
154	i386_set_gsbase(kcb);
155}
156
157/* Get the current kcb. */
158static __inline struct kcb *
159_kcb_get(void)
160{
161	return (_kcb_curkcb());
162}
163
164static __inline struct kse_thr_mailbox *
165_kcb_critical_enter(void)
166{
167	struct kse_thr_mailbox *crit;
168
169	crit = _kcb_readandclear_tmbx();
170	return (crit);
171}
172
173static __inline void
174_kcb_critical_leave(struct kse_thr_mailbox *crit)
175{
176	_kcb_set_tmbx(crit);
177}
178
179static __inline int
180_kcb_in_critical(void)
181{
182	return (_kcb_get_tmbx() == NULL);
183}
184
185static __inline void
186_tcb_set(struct kcb *kcb, struct tcb *tcb)
187{
188	kcb->kcb_curtcb = tcb;
189}
190
191static __inline struct tcb *
192_tcb_get(void)
193{
194	return (_kcb_curtcb());
195}
196
197static __inline struct pthread *
198_get_curthread(void)
199{
200	struct tcb *tcb;
201
202	tcb = _kcb_curtcb();
203	if (tcb != NULL)
204		return (tcb->tcb_thread);
205	else
206		return (NULL);
207}
208
209static __inline struct kse *
210_get_curkse(void)
211{
212	return ((struct kse *)_kcb_curkse());
213}
214
215void	_i386_enter_uts(struct kse_mailbox *km, kse_func_t uts, void *stack,
216    size_t stacksz);
217
218static __inline int
219_thread_enter_uts(struct tcb *tcb, struct kcb *kcb)
220{
221	int ret;
222
223	ret = _thr_getcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext);
224	if (ret == 0) {
225		_i386_enter_uts(&kcb->kcb_kmbx, kcb->kcb_kmbx.km_func,
226		    kcb->kcb_kmbx.km_stack.ss_sp,
227		    kcb->kcb_kmbx.km_stack.ss_size);
228		/* We should not reach here. */
229		return (-1);
230	}
231	else if (ret < 0)
232		return (-1);
233	return (0);
234}
235
236static __inline int
237_thread_switch(struct kcb *kcb, struct tcb *tcb, int setmbox)
238{
239	extern int _libkse_debug;
240
241	if ((kcb == NULL) || (tcb == NULL))
242		return (-1);
243	kcb->kcb_curtcb = tcb;
244	if (_libkse_debug == 0) {
245		tcb->tcb_tmbx.tm_lwp = kcb->kcb_kmbx.km_lwp;
246		if (setmbox != 0)
247			_thr_setcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext,
248			    (intptr_t)&tcb->tcb_tmbx,
249			    (intptr_t *)(void *)&kcb->kcb_kmbx.km_curthread);
250		else
251			_thr_setcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext,
252				0, NULL);
253	} else {
254		if (setmbox)
255			kse_switchin(&tcb->tcb_tmbx, KSE_SWITCHIN_SETTMBX);
256		else
257			kse_switchin(&tcb->tcb_tmbx, 0);
258	}
259
260	/* We should not reach here. */
261	return (-1);
262}
263
264#endif
265